A fast and label-free detection of hydroxymethylated DNA using a nozzle-jet printed AuNPs@Ti3C2 MXene-based electrochemical sensor

• Published in: Talanta (Oxford) Vol. 244; p. 123421
• Main Authors: Bhat, Kiesar Sideeq, Byun, Seongjun, Alam, Asrar, Ko, Myunggon, An, Jungeun, Lim, Sooman
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.07.2022
• Subjects: 5-hydroxymethylcytosine; Cancer biomarker; DNA base-Gold affinity interaction; Electrochemical sensor; Gold nanoparticles; Ti3C2 MXene nanosheets; Cancer biomarker; Ti3C2 MXene nanosheets; DNA base-Gold affinity interaction; Electrochemical sensor; Gold nanoparticles; 5-hydroxymethylcytosine
• ISSN: 0039-9140; 1873-3573
• DOI: 10.1016/j.talanta.2022.123421

5-hydroxymethylcytosine (5hmC) is a key epigenetic mark in the mammalian genome that has been proposed as a promising cancer biomarker with diagnostic and prognostic potentials. A new type of two-dimensional (2D) material called MXene includes transition metal carbides and nitrides and possesses unique physico-chemical properties suitable for diverse applications, including electrochemical sensors. Here, we report a new nozzle-jet printed electrochemical sensor using gold nanoparticles (AuNPs)@Ti3C2 MXene nanocomposite for the real-time and label-free detection of 5hmC in the genome. We utilized Ti3C2 MXene as a platform to immobilize AuNPs, which have been shown to exhibit different affinity interactions toward 5-methylcytosine (5 mC) and 5hmC, and thus produce distinct electrochemical responses. To fabricate the electrode, a highly conductive and adhesive silver ink was prepared to generate a silver line onto polyethylene terephthalate (PET) substrate using nozzle-jet printing, followed by deposition of AuNPs@Ti3C2 MXene ink at one end via dropcasting. Analyses of morphology and chemical composition showed that all steps of the sensor fabrication were successful. The fabricated sensor coupled with cyclic voltammetry showed excellent performance in distinguishing 5 mC- or 5hmC-enriched cellular genomic DNAs. As a proof-of-concept investigation, we confirmed that our sensor readily and consistently detected 5hmC diminution in multiple tumors, compared to the paired normal tissues. Thus, our simple and cost-effective sensing strategy using printable AuNPs@Ti3C2 MXene ink holds promise for a wide range of practical applications in epigenetic studies as well as clinical settings. [Display omitted] •A novel, label-free electrochemical biosensor based on AuNPs@Ti3C2 MXene for the quick, reliable, and real-time detection of 5hmC-enriched DNAs.•Verification of functionality in distinguishing cellular genomic DNAs containing different levels of 5hmC.•Successful and consistent detection of diminished 5hmC levels in the primary cancer genome, compared to that of neighboring normal tissues.